Muffler



Dec. 23, 1924. 1,520,090y

s. w. SCOFIELD ET AL MUFFLER Filed Oct. 13, 1919 3 Sheets-Sheet 1 nec, 23, 1924.

s. w. SCOFIELD ET AL 1520090 MUFFLER 3 Sheets-Sheet 2 @www I-Dec. 23, 1924.

1,520,690 S. W. SCOFIELD ET AL l MUFFLER Fiied oct. 15, 1919 3 Sheets-Sheet '5 Patented Use., 23, i924.

UNETED STATES PATENT OFFICE.

SHERMAN Vif. SCOFIELD AND MARTN W'. MUEHLI-IAUSER, OF CLEVELAND, OHIO.

MUFFLER.

Application ed Getober 13, 1919.

To all 'whom t may concern.'

Bc it known that we, SHERMAN iV. SoorrnLD and MARTIN TV. MUnrrLHAUsnn, citizens oic the United States, residents ot Cleveland, county of Cuyahoga, and State ol Ohio, have invented new and useful lmprovements in Muii'lers, of which the following is a specification, the principle ot the invention being herein explained and the best mode in which we have contemplated applying that principle, so as to distinguish it from other inventions.

Our invention relates to mulllers, and particularly to a suction muiller adapted for use with internal combustion engines. rl`he invention is designed to provide an apparatus of this character in which the muliling means are self-operated, i. e., the suctionproducing means are not positively operated by an extraneous driving power but driven by the pressure ot the expanding exhaust gases 'trom the cylinders; in which the mailling action shall be very etlicient; and in which the reduction ot the power output, due to the battling action, shall be kept at a minimum.

The annexed drawings and the following description set forth in detail certain means embodying our invention, the disclosed means, however, constituting but one ot the various mechanical forms in which the principle ot the invention may be employed.

In said annexed drawings:

Figure l represents a broken side elevation, oit our improved mull'ler, in combination with fragmentary parts of the cylinders ot an internal combustion engine with which the same is connected;

Figure 2 represents a plan view ot our improved multier;

Figure 3 represents a fragmentary horizontal section of a casing within which 'the suction-creating means are disposed, said means being, inthe form ont device illustrated, two sets o'l' 'lian blades, an enlarged diagranm'iatic view of the saine being shown in said ligure;

Figure Ll represents, upon an enlarged scale, a longitudinal vertical section, taken in the plane indicated by the line lV-llf, Figure 2, the 'fan blades being shown in iull;

Figure 5 represents a lateral tace view ot the two sets ot tan blades; also a vertical transverse section ot 'the containing casing;

Figure represents a central vertical Serial No. 330,200.

transverse section, taken in the plane indicated by the line Vl-Vl, Figure 4;

Figure 7 represents a fragmentary horizontal section, taken in the plane indicated by the line Vil-VH, Figure 6;

Figures 8, 9, 10, ll and l2 represent di'llerent views ot a common shaft upon which two sets of tan blades are mounted, only one blade ot each set being shown, said views comprising respectively, Figure 8, a side view; Figure 9, a bottom plan view from the plane indicated by the line IX-IX, Figure 8; Figure l0, a plan view trom the side opposite to that trom which Figure 9 is talzen, as indicated by the line XMK, Figure 8; Figures l1 and l2 end elevations, taken :troni the planes indicated by the lines Ll-X and Kil-XH, respectively, Figure 8.

Referring `to the annexed drawings, Figure l, an exhaust pipe from the cylinders of an internal combustion engine is indicated by the ordinal l, the same communicating with the cylinders 2 and adapted to be connected to a pipe 3 serving as an intake pipe in our improved muffler tor the exhaust gases trom said cylinders. The mufller proper is contained within a cylindrical casing coniprised of the two members t and integrally secured together by means of flanges 4 and 5 and suitable bolts, as plainly shown in Figures 2 and 5. This casing is subdivided by means ot' a partition member 6, the same being a circular plate whose marginal edge is secured between the ianges 4 and 5 oi' the casing members et and 5. This partition member 6 is formed with a central aperture G providing' communication between the compartments 7 and S formed in the casing by said partition member 6. suitably secured to the inner side faces otl the casing are bearing members 0 and l() within which l are journalcd the ends of a shaft ll, said shaitt intersecting the central aperture G of the partition G. Special lubricating means are provided for the journal ends ot the shalt l1, the same consisting ot metal l2 within which is imbedded graphite or other suitable lubricating material. The shaft 1l is Vformed with two enlarged cylindrical hub portions ll, one within each otl the compartments T and S. Mounted upon the shat't ll and secured within these enlarged hub members il are two sets ot 'lian blades 13 and lll. The exact means tor mounting the tan blades consist ot two series ot stems or holders 13 and 14 integrally secured within said hub members 11 and secured at their outer ends to the rear faces of said fan blades 13 and 1K1, as plainly shown in Figures 4, 5 and 6. The inner edges of the blades 13 and 14: are tapered, as indicated by 133 and 143, Figure 6, and the extreme inner portion of said blades consist of narrow tongue members 132 and 142 disposed in suitable slots 112 cut in the hub members 11', said tongues 132 and 142 extending laterally from said slots and being bent back flush against the side faces of said hub members 11.

The exhaust gases from t-he pipe 1 enter the compartment 7 through the inlet pipe 3 and impinge upon the said fan blades 13. These gases leave the casing formed by the members d: and 5 through the compartment S, escaping through the outlet pipe 15, Figures 1, 2 and 1. The two sets of fan blades 13 and 14e are set at an angle to the axis of the shaft 1.1, the set 13 being set one angle, and the set 14 being set at another angle. These angularities and the relation between them is plainly indicated by the developed view in Figure 3. As shown in Figure the pipes 3 and 15 form tangential inlet and discharge passages, respectively, opening into the compartments 7 and 8 of the muffler through the cylindrical walls 42 and 52 thereof adjacent the top. The exhaust gases are discharged from the engine manifold through the pipe 3 to the compartment 7 of the muffler in intermittent rapidly moving puffs, each of which consists of a body of gas having a high pressure adjacent the forward end thereof and a gradually decreasing pressure from the high pressure point back to the manifold. The forward high pressure portion of each puff impinges against the fan blades 13 in the compartment 7 in'iparting rotative movement to the shaft 11 which carries the blades 141 in the compartment 8 as well as the blades 13. The inclination of the blades 13 is such as to force the gases toward the partition 6 and maintain a high pressure adjacent said partition to facilitate the movement of the gases into the compartment 8. The inclination of the fan blades 14 is suoli that the rotary movement caused by the gas stream tends to force the gases away fromv the partition 6 toward the outer side wall 5 of the compartment 8 and by centrifugal action to discharge the gases through the. tangential outlet passage 15. The rotation of the fan blades 15 creates suction through the axial passage Gl in tl'irough the partition 6 and quickly relieves the initial pressure in the chamber 7 due to the entrance thereinto of the high pressure portion of the puff. The passage of the himi pressure portion of the puff through the two fans results in the expenditure of a portion of the kinetic energy of the moving in rotating the fans and the momentum imparted to the fans by the high pressure portion of the puff causes a suction in the passage 3 which accelerates the lagging portion of the gas discharge from the engine cylinder and establishes a low pressure in the pipe 3 and manifold at the time when a succeeding puff of gas is discharged from an engine cylinder.

The capacities of the two fans are so proportioned that successive pufl's of spent gases from the engine cylinders enter the compartment 'T before the preceding puffs are entirely discharged. The action of the fans is to retard the forward high pressure portion of each puff employing a portion of the kinetic energy thereof to accelerate the movement of the fans, the momentum of the fans due to the passage of the high pressure portion of the puff accelerating the movement of the lagging portion of the puff whereby the successive puffs are discharged in a substantially uniform stream through the passage 15, practically eliminating the noise of exhaust, and whereby low pressure is established in the engine manifold and passage 3 at the instant of each discharge from an engine cylinder, eliminating the bock pressure and consequent reduction of power which is an inherent disadvantage in mufflers as heretofore designed.

It has been found that by setting the fan blades 13 and`11 at substantially the angularities shown, the flow of gas through the muffler is properly regulated to effect the results described. However it is to be understood that this exact arrangement of fan blades is not essential to our invention but merely illustrative of that embodiment of our invention which we have found most efficient.

lVhat We claim is:

1. A muffler comprising, in combination with a cylindrical casing provided with an inlet and tangential inlet and outlet passages disposed in different planes perpendicular to the casing axis; a partition disposed in said casing, perpendicular to the axis of the latter, and dividing the same into a pair of compartments, one of the latter communieating with said inlet and the other coniniunicating with said outlet, a shaft rotatably supported in said casing, two sets of fan blades mounted upon Said shaft in said compartments, respectively, said fans adapted to be rotated by the exhausting gases, and means providing` communication between said compartments, one set of said fan blades being set at different angles, respectively, to the axis of said shaft, the fan blades in the inlet compartment being set at an angle to the axis of said shaft materially greater than the angle at which said outletcon'ipartment blades are set, whereby a suction is created in said inlet compartmentand gases ancl delivered therefrom to said outlet compartment and also drawn from the inlet compartment and delivered through said outlet compartment to said outlet.

2. A inuiller for use with internal eoinbustion engines comprising a easing provided with an inletI and ineens directly eonnecting said inlet With the cylinder exhaust, said Casing being formed also with an out- 10 let, 2i partition disposed in said casing und 

